1. Field of the Invention
This invention relates to an assembly of beam splitters, and more particularly, to a rangefinder utilizing the assembly of beam splitters.
2. Description of the Related Art
FIG. 1 schematically shows a conventional optical rangefinder, which is disclosed in U.S. Pat. No. 6,441,887. In this patent, the optical range-finder 10 includes a viewing/emitting optical system 11 and a receiving system 12; wherein the viewing/emitting optical system 11 includes a prism unit 13, a first object lens 14, an emitter 15, a display 16 and an ocular lens 17. After measuring the distance between the user and the object, the display 16 shows the distance.
In this optical rangefinder 10, the display 16 is a transmitted LCD. When visible light enters the viewing/emitting optical system 11, the display 16 shows the distance by passing visible light through the display 16. However, the optical rangefinder 10 is used in the dark environment, only a few light enters the viewing/emitting optical system 11. Therefore, the data shown by the LCD 16 is indistinct.